Hide OpenGL loading screen

See merge request STJr/SRB2!349

FOF wall slope skewing backport

See merge request STJr/SRB2!341

Add example SQL file.

See merge request STJr/SRB2!330

Update server name insantly

See merge request STJr/SRB2!344

Fix glitches with flats visible when looking up/down in 1st person (software renderer fix)

See merge request STJr/SRB2!282

Print copyright notice in stdout console on program start

See merge request STJr/SRB2!347

Last min cleanup

See merge request STJr/SRB2!342

CMake: Use internal libs.

See merge request STJr/SRB2!325

Update source copyrights to 2018

See merge request STJr/SRB2!346

Extra credits update .21

See merge request STJr/SRB2!345

# Conflicts:
#	src/r_segs.c

Fix M_FindResponseFile returning garbage data

See merge request STJr/SRB2!254

Render the skies correctly on splitscreen in OpenGL mode

Render the startup screen on OpenGL mode

m_fixed: asm: cc is not a register

Add myargmalloc boolean to detect whether we allocated myargv ourselves or not, so we don't free myargv if we didn't

2.1.21 credits update

See merge request STJr/SRB2!339

Add README and LICENSE for installs

See merge request STJr/SRB2!335

Make the credits pics darker

See merge request STJr/SRB2!336

Make the error less confusing

See merge request STJr/SRB2!337